292 



THE AGRICULTUPiAL XEWS. 



September 12, 1914. 



FRUIT m FRUIT TREES. 



COCO-NUT EXPERIMENTS IN CEYLON. 



Ill the West Indies there is at tlie present time a consid- 

 erable want of accurate information coni-erning the manuring 

 and cultivation of coco-nuts. Such information, to some 

 extent applicable under West Indian conditions, is contained 

 in Bulletin No. 10 of the Department of Agriculture, Ceylon, 

 entitled, Coco-nuts; E.xperimeiits at Peradenyia. The trials 

 which this Bulletin describe.s constitute a continuation of 

 those dealt with in Bulletin No. 2, published in December 

 1912, and bring.s the result.s of three years' experimenting 

 up to date. The work has been concerned principally with 

 the question of manuring, and the coco-nut.s that received 

 the treatments were all old, growing on a quartzy loam at 

 an elevation of about 1,600 feet and situated about 51 miles 

 from the sea in a direct line. The average rainfall in this 

 di.strict Is just over 83 inches, but the precipitation varied 

 fro'u 62 inches in 1908 to 120 inches in 1913. The climate 

 is hot, and February to August are usually the dry months, 

 wlien the soil becomes hard and unworkable. It will be 

 .seen that the climatic conditions ditTer from those under 

 which large areas of coco-nuts are grown in the West Indies, 

 liut the results will no doubt be to some extent applicable 

 under condition.s obtaining in Trinidad and British Guiana. 



The chief object of the e.xperimeiits was to ascertain 

 how far old coconut palms can be improved by means avail- 

 able to most cultivators. Also the effect of the chief 

 manurial constituents alone and in combination on the 

 development and formation of nuts. 



In reviewing the results olitained it may be stated first 

 of all, in order to indicate the general value of these experi- 

 ments, that those trees which I'eceived no treatment of any 

 kind showed a gradual falling off in yield. 



Plot 1 in the manurial experiments received common 

 salt, and the number of matured nuts per pound .steadily 

 decreased, though the number of nut.s per candy of copra wa.s 

 found to Ije very high, namely 1,900. The percentage of 

 oil .showed some falling ott', and it is concluded that 

 salt alone as a manure for coco-nuts has apparentlj' not 

 that value usually ascribed to it On plot 2, sulphate 

 of potash was used. Here the number of matured nuts 

 per tree .showed some increase and the number of nuts per 

 candy of copra was high, l)ut there was a falling oW in the 

 percentage of oil. The fronds of the palms looked more 

 healthy than those on trees which had lieen treated with 

 common salt. One of the most disappointing plots in these 

 interesting trials seems to have been that which was dressed 

 with nitrate of soda. The palms still showed weak, yellowish, 

 and small bunches of nuts. The percentage of matured nuts 

 to flowers fell off heavily, but the numlier of nuts per candy 

 of copra still remained very high. Plot 4 was dressed with 

 phosphoric acid at the rate of 200 Hi. per acre. The palms all 

 looked healthy and vigorous as a result of this treatment and 

 .showed a marked improvement. The number of matured 

 nuts per tree increased, )jut the percentage of matured nuts 

 to female flowers fell nearly 10 per cent. In the green man- 

 ure plots (No. 5) the percentage of matured nuts to 

 flowers exhibited a falling oft', and as this manure mixture 

 supplied all the chief mineral constituents required, it is 

 believed that the high proportion of immature nuts is 

 proljably due more to climatic ett'ect.s than to want of plant 

 food; but this point reijuires further investigation. A marked 

 improvement in the appearance of tlie trees and some improve- 



ment in yield per tree was obtained by digging in green 

 manure with basic slag and sulphate of potash. In this plot 

 the percentage of oil increased, which did not occur in the 

 case of the previous plots; but the nuts were small. 



.\ very interesting form of treatment was that employed 

 on plot 8 where tlie soil was ploughed twice annually. Here 

 the number of matured nuts per tree increased from 29-2 in 

 1911 to 44 'o in 1913 — the most satisfactory increa.se of all the 

 plots. The number of nuts per candy of copra was, however, 

 the poorest of all — a fact that is difticult to explain. The 

 percentage of oil fell slightly. Soluble manure was applied 

 to plot 9 and gave fairly satisfactory results. In plot 10, to 

 which lime was ajiplied at the rate of 300 lb. per acre, 

 followed liy tlie general mixture of plot 5, there was no very 

 marked improvement. In the next plot the green dressing 

 Teplirositi purpurea (for some time under trial in the AVest 

 Indies) was dug in with basic slag and sulphate of potash 

 with unsatisfactory I'esults. Cattle manuring practised in the 

 case of jilot 12 gave fairlj- satisfactory results, the fact <)f 

 most interest Ijeing that there was a considerable increase in 

 the percentage of oil. 



The control plot No. 1 4. which was unmanuretl, is 

 naturally of special interest in considering the results of tliese 

 experiments. It showed a distinct falling ott" in yield oi 

 matured nuts from 30'6 in 1911 to 25 in 1913, and there was 

 very little increase in the total amount of flowers and the 

 percentage of matured nuts, which were .small. But the per- 

 centage of oil increased from 50"5 to 64 per cent, in 1913 — 

 an observation of some interest. Plot 15 was also used as 

 a control. In this case also there was a fa.ling ofi' in yield. 

 A comparison of the number of matured nuts from the 

 manured and lailtivated plots and the unmannred plots 

 respectively, since the experiments were begun in 1911, 

 shows that the unnianured plots yielded rather more than the, 

 manured plots the flrst year, and then steadily decreased, the 

 only manureil plot falling otf in the .same way being No. 1 

 manured with oOO lb. of common salt per acre per annum. 



The results of these experiments will be more valuable 

 as time passes, but meanwhile they tend to show tliat: 



(1) 'Dlougliing twice a year is as beneficial as manuring'; 



(2) 'tying cattle in 1911 and 1912 had an immediate ettcct 

 lasting over two years, no cattle having been available for 

 tying in 1913"; (3) 'the application of a soluble mixture twice 

 annually and a general mixture annually iirodui-ed a steady 

 increa.se maintained during 1913'; (4) 'green manure with 

 basic slag and sulphate of potash showed a marketl improve- 

 ment, which, liowever, was not fully maintained during the 

 wet season of 1913'; (5) 'the application of salt or nitrate of 

 soda has had no beneficial effect during the three years' experi- 

 menting'; (6) 'no treatment of any kind results in the gradual 

 falling ott" in yield'. 



A critical examjnation of the numerical results raises 

 several interesting j)(,nnts that undoubtedly recjuire further 

 investigation, one of the most curious being that whilst the 

 total number of mature and immature nuts increased annu- 

 ally, the proportion of female flowers that produced mature 

 fruits showed a steady decrease during the same period. 



Appended to the interesting information abstracted aliove 

 are the tables containing figures to show the amount of ferti- 

 lizers applied and the various yields of nuts and flowers in 

 detail. This is well worth careful reference by those who 

 are concerned with the cultivation of coco-nuts, and the 

 publication under consideration may be .said to contain 

 valuable and fairly conclusive information, which is some- 

 what rare at the present time in connexion with coco-nuts. 



